STUDY OF PARAMETERS TO PRODUCE QUALITY CASTINGS BY CENTRIFUGAL PROCESS

Abstract

Centrifugal casting process was investigated as a method of producing quality castings. The castings Were made using commercially pure aluminium. The parameters investigated were mould rotational speed, pouring rate, pouring temperature, preheating of the mould and mould lining. The effect of these parameters was seen on the following characteristic of quality casting tensile strength, Brinell hardness, surface roughness and porosity of the casting. - For this purpose a prototype horizontal axis centrifugal casting machine has been used. A new pouring device system was designed and fabricated. In order to achieve the optimum conditions the mould rotational speed range was 1100-130,0 RPM. The pouring rate was in the range 370-510 gm/sec. Preheating of the mould was fixed in the range 200-300°C which was necessary for good surface finish. The pouring temperature of the molten metal was 750-850°C. This investigation was planned with 4 factorial experimental design with three levels for each factor. ii iii Castings examined shows that the above parameters have a significant effect on the strength of the casting produced. Tensile strength testing of the prepared specimen was made with Housefield tensometer, for Hardness test the Brinell testing method was used. Surface roughness is being measured with the light section measuring equipment. Specimen were also prepared for testing the porosity of the castings. Models to predict the criteria for testing the, quality of castings were made' in the form of regression equations relating the various process parameters with these criteria. Experiments shows that coating of the mould with Black graphite gives a good result regarding the surface finishing.